var bt = document.getElementById("bt");
var btimg = document.getElementById("btimg");
var area = document.getElementById("area");
bt.onclick = function(){
    if(btimg.style.transform = "rotate(180deg)"){
        area.style.display = "block";
        btimg.style.transform = "rotate(0deg)";
    }
};
area.onclick = function(){
    area.style.display = "none";
    btimg.style.transform = "rotate(180deg)";
}
var bx = document.getElementById("benxiao");
var gz = document.getElementById("guanzhu");
var picture = document.getElementById("picture");
var picture2 = document.getElementById("picture2");
bx.onclick = function(){
    bx.style.backgroundColor = "#000";
    bx.style.color = "#fff";
    gz.style.backgroundColor = "#f6f6f6";
    gz.style.color = "#000";
    picture.style.display = "block";
    picture2.style.display = "none";
}
gz.onclick = function(){
    gz.style.backgroundColor = "#000";
    gz.style.color = "#fff";
    bx.style.backgroundColor = "#f6f6f6";
    bx.style.color = "#000";
    picture.style.display = "none";
    picture2.style.display = "block";
}